Scientists discover new way to determine when water was present on Mars and Earth

A record of the past may be locked inside a mineral common to both planets

The discovery of the mineral jarosite in rocks analyzed by the Mars Rover, Opportunity, on the Martian surface had special meaning for a team of Syracuse University scientists who study the mineral here on Earth. Jarosite can only form in the presence of water. Its presence on Mars means that water had to exist at some point in the past. The trick is in figuring out if jarosite can be used as a proxy for determining when, and under what conditions, water was present on the planet. Read more...